Fire-retardant fluid coupling assembly and method

Abstract

A pipe coupling assembly (10, 46, 64) and method of manufacturing the same involves the use of a pipe coupling (12, 50, 66) with an intumescent collar (14, 68) and a metallic band (16, 56, 70) wrapped thereabout at one end thereof. The metallic band has overlapping ends (36, 38) which are held together by elongated fasteners (18, 60) passing through overlapping portions and into the intumescent wrap. The pipe coupling assembly including a tubularly-shaped main body, an intumescent collar, and a metallic band are assembled as a unit in a factory to be later placed in a concrete form to have concrete poured thereabout. A heat receiving edge of the metallic band receives heat from a fire in a space below a barrier in which the pipe coupling assembly is embedded and conducts it to the outer periphery of the intumescent collar.

The embodiments of the invention in which an exclusive property or privilege are claimed are defined as follows: 
     
       1. A method of constructing a pipe coupling assembly product at a factory separate from an installment site and then transporting the pipe coupling assembly product to said installment site for permanent engagement with other pipes, said method comprising the steps of: at said factory, choosing a pipe coupling having an elongated tubularly-shaped main body with opposite first and second ends and inner and outer surfaces;   at said factory, wrapping an intumescent collar about the outer surface of said tubularly-shaped main body near the first end thereof with a corresponding first end edge of said intumescent collar being adjacent said first end of said elongated tubularly-shaped main body, said intumescent collar being constructed of a material which expands when it gets hot to close off the inner surface of said tubularly-shaped main body;   at said factory, placing a metallic band about the circumferential periphery of said intumescent collar, said metallic band having one heat receiving edge extending to the end of said elongated tubularly-shaped main body at which said intumescent collar is wrapped but leaving said first end edge of said intumescent collar at least partially uncovered;   at said factory, fastening said metallic band to said intumescent collar and said intumescent collar to the outer surface of said tubularly-shaped main body thereby forming said pipe coupling assembly product;   shipping said pipe coupling assembly product as a unit from said factory to said installment site for permanent engagement with other pipes;   thereby forming a pipe-coupling assembly product at said factory separate from said installment site, which is then shipped and stored as a unit and which can be later placed at said installment site and attached to a concrete form, with wet concrete being poured into said form about said pipe coupling assembly product and allowed to cure around said pipe coupling assembly product to form a barrier, the form being thereafter removed from said barrier and pipes being attached to opposite ends of the tubularly-shaped main body with the first end of the intumescent collar and the heat receiving edge of the metallic band being exposed at a surface of said barrier to form a fire proof pipe string.   
     
     
       2. The method of making the pipe-coupling assembly product as in claim 1 wherein the step of placing said metallic band about the circumferential periphery of the intumescent collar comprises wrapping a metallic band having first and second ends about said intumescent collar so that said first and second ends overlap one with the other, and then inserting a fastener through both end portions thereby holding said end portions together and forming a ring of said metallic band about said intumescent collar, said fastener extending into the intumescent collar, thereby fastening said metallic band to said intumescent collar. 
     
     
       3. The method of making the pipe-coupling assembly product as in claim 2 wherein said fastener is constructed of metal, thereby forming a heat conductor from said metallic band into said intumescent collar. 
     
     
       4. The method of making the pipe-coupling assembly product as in claim 3 wherein is included the step of mounting additional protrusions on said metallic band extending into said intumescent collar. 
     
     
       5. The method of making the pipe-coupling assembly product as in claim 1 wherein the step of placing said metallic band about the circumferential periphery of the intumescent collar comprises the steps of wrapping a metallic band having first and second ends about said intumescent collar so that said first and second ends overlap with one another, and then fastening the two overlapping end portions one with the other.